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    Re: The Noon Fix
    From: John Karl
    Date: 2009 Apr 13, 20:47 -0700

    Peter-- Yes, Table one is the same correction we have been talking
    about.  The entries in the table are computed from Corr = 0.016667*
    Vground*4 min* Cos(Zn).  The 0.0166667 is one knot of speed in miles
    per minute.  This is exactly what we have been saying the correction
    is for a moving ship.  BTW, this correction is substantially in error
    at high speeds as the time between observations gets longer (Not
    relevant for sailors).  But I'm surprised this simple linear
    correction works so well for the highly nonlinear altitude equation.
    The Coriolis force of Table 9 is unrelated.  It's the same force that
    makes winds aloft run nearly parallel to the isobars instead of
    perpendicular to them.  The same force deflects the bubble in a bubble
    sextant from the vertical.    The Coriolis force is v*W*sin(A), v is
    the velocity of the craft and w is the earths rotational speed (in
    radians per time), and "A" is the angle between V and W.
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